Devices and methods for optical detection of tissue contact

ABSTRACT

A method of directing energy to tissue includes the initial step of positioning an energy applicator for delivery of energy to target tissue. The energy applicator is provided with a surface-contact detection device including one or more optical transmitters and one or more optical receivers. The energy applicator is operably associated with an electrosurgical power generating source. The method also includes the steps of determining whether a radiating portion of the energy applicator is disposed in contact with the target tissue based on a determination of whether optical signals generated by the one or more optical transmitters result in reflected optical signals received at the one or more optical receivers, and if it is determined that the radiating portion of the energy applicator is disposed in contact with tissue, transmitting energy from the electrosurgical power generating source through the radiating portion to the target tissue.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. patent application Ser.No. 14/018,081 filed on Sep. 4, 2013, now U.S. Pat. No. 9,522,033, whichclaims priority to U.S. Provisional Application No. 61/708,930 filed onOct. 2, 2012, the entire contents of each of which are incorporatedherein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to electrosurgical systems and devicesfor performing medical procedures. The present disclosure also relatesto detection devices for use in connection with electrosurgical devices.More particularly, the present disclosure relates to systems, devicesand methods for optical detection of surface contact of anelectrosurgical device surface to tissue. The present disclosure alsorelates to electrosurgical devices including a waveguide with dielectricstructures. The present disclosure also relates to electrosurgicaldevices including a waveguide with removable dielectric structures. Thepresent disclosure also relates to methods of directing energy to tissueusing the same.

2. Discussion of Related Art

Electrosurgical instruments have become widely used by surgeons.Electrosurgery involves the application of thermal and/or electricalenergy to cut, dissect, ablate, coagulate, cauterize, seal or otherwisetreat biological tissue during a surgical procedure. Electrosurgery istypically performed using a handpiece including a surgical instrument(e.g., end effector, ablation probe, or electrode) adapted to transmitenergy to a tissue site during electrosurgical procedures, anelectrosurgical generator operable to output energy, and a cableassembly operatively connecting the surgical instrument to thegenerator.

Treatment of certain diseases requires the destruction of malignanttissue growths, e.g., tumors. Electromagnetic radiation can be used toheat and destroy tumor cells. Treatment may involve inserting ablationprobes into tissues where cancerous tumors have been identified. Oncethe probes are positioned, electromagnetic energy is passed through theprobes into surrounding tissue.

In the treatment of diseases such as cancer, certain types of tumorcells have been found to denature at elevated temperatures that areslightly lower than temperatures normally injurious to healthy cells.Known treatment methods, such as hyperthermia therapy, heat diseasedcells to temperatures above 41° C. while maintaining adjacent healthycells below the temperature at which irreversible cell destructionoccurs. These methods involve applying electromagnetic radiation toheat, ablate and/or coagulate tissue. Microwave energy is sometimesutilized to perform these methods. Other procedures utilizingelectromagnetic radiation to heat tissue also include coagulation,cutting and/or ablation of tissue.

Electrosurgical devices utilizing electromagnetic radiation have beendeveloped for a variety of uses and applications. A number of devicesare available that can be used to provide high bursts of energy forshort periods of time to achieve cutting and coagulative effects onvarious tissues. There are a number of different types of apparatus thatcan be used to perform ablation procedures. Typically, microwaveapparatus for use in ablation procedures include a microwave generatorthat functions as an energy source, and a microwave surgical instrument(e.g., microwave ablation probe) having an antenna assembly fordirecting the energy to the target tissue. The microwave generator andsurgical instrument are typically operatively coupled by a cableassembly having a plurality of conductors for transmitting microwaveenergy from the generator to the instrument, and for communicatingcontrol, feedback and identification signals between the instrument andthe generator.

There are several types of microwave probes in use, e.g., monopole,dipole and helical, which may be used in tissue ablation applications. Amicrowave transmission line typically includes a thin inner conductorthat extends along the longitudinal axis of the transmission line and issurrounded by a dielectric material and is further surrounded by anouter conductor around the dielectric material such that the outerconductor also extends along the transmission line axis.

Dielectric properties of biological tissues are determining factors forthe dissipation of electromagnetic energy in the body. Tissue impedancecan vary widely among tissue types and can vary according to the qualityand quantity of fluids surrounding the tissue. For tissue ablationpurposes, there is a need to match the impedance of the microwavetransmission line to the impedance of the tissue.

SUMMARY

According to an aspect of the present disclosure, an electrosurgicaldevice is provided. The electrosurgical device includes asurface-contact detection device including a lens member, one or moreoptical transmitters to generate optical signals, and one or moreoptical receivers to receive optical signals reflected by the lensmember. The lens member is adapted to allow the one or more opticaltransmitters and the one or more optical receivers to communicate whenthe lens member is disposed in contact with tissue.

According to an aspect of the present disclosure, an electrosurgicalsystem is provided. The electrosurgical system includes an energyapplicator adapted to direct energy to tissue, an electrosurgical powergenerating source, and a surface-contact detection device. Thesurface-contact detection device is operably associated with the energyapplicator. The surface-contact detection device iscommunicatively-coupled to the electrosurgical power generating source.The surface-contact detection device includes at least one or moreoptical transmitters to generate optical signals, a lens memberconfigured to reflect optical signals generated by the one or moreoptical transmitters when the lens member is disposed in contact withtissue, and one or more optical receivers to receive optical signalsreflected by the lens member. The electrosurgical power generatingsource is adapted to transmit energy to the energy applicator when it isdetermined that the lens member is disposed in contact with tissue.

One or more operating parameters associated with the electrosurgicalpower generating source may be controlled based on an electrical signalreceived from the surface-contact detection device.

In any one of the aspects, the lens member is configured to reflectoptical signals generated by the one or more optical transmitters whenthe lens member is disposed in contact with tissue.

According to another aspect of the present disclosure, anelectrosurgical device is provided. The electrosurgical device includesan energy applicator adapted to direct energy to tissue. The energyapplicator includes an antenna assembly. The antenna assembly includes awaveguide. The waveguide includes an open end andelectrically-conductive walls defining a cavity therein. The cavity isdisposed in communication with the open end. A first dielectricstructure including a plurality of dielectric layers is disposed atleast partially within the cavity. A second dielectric structure isdisposed distally to the distal end of the waveguide walls and coupledto the distal end of the first dielectric structure. One or more of thedielectric layers of the first dielectric structure disposed at leastpartially within the cavity are adapted to be removable from thewaveguide.

According to another aspect of the present disclosure, anelectrosurgical system is provided. The electrosurgical system includesan energy applicator adapted to direct energy to tissue, anelectrosurgical power generating source, and a surface-contact detectiondevice operably associated with the energy applicator. The energyapplicator includes an antenna assembly including a waveguide thatincludes an open end and electrically-conductive walls defining a cavitytherein. The cavity is disposed in communication with the open end. Theenergy applicator further includes a dielectric structure including aplurality of dielectric layers. The dielectric structure is disposed atleast partially within the cavity. The surface-contact detection deviceis communicatively-coupled to the electrosurgical power generatingsource. The surface-contact detection device includes one or moreoptical transmitters to generate optical signals, a lens memberconfigured to reflect optical signals generated by the one or moreoptical transmitters when the lens member is disposed in contact withtissue, and one or more optical receivers to receive optical signalsreflected by the lens member. The electrosurgical power generatingsource is adapted to transmit energy to the energy applicator based on adetermination that optical signals generated by the one or more opticaltransmitters result in reflected optical signals received at the one ormore optical receivers.

According to another aspect of the present disclosure, a method ofdirecting energy to tissue is provided. The method includes the initialstep of positioning an energy applicator for delivery of energy totarget tissue. The energy applicator is provided with a surface-contactdetection device including one or more optical transmitters and one ormore optical receivers. The energy applicator is operably associatedwith an electrosurgical power generating source. The method alsoincludes the steps of determining whether a radiating portion of theenergy applicator is disposed in contact with the target tissue based ona determination of whether optical signals generated by the one or moreoptical transmitters result in reflected optical signals received at theone or more optical receivers, and if it is determined that theradiating portion of the energy applicator is disposed in contact withtissue, transmitting energy from the electrosurgical power generatingsource through the radiating portion to the target tissue.

The method may further include the step of determining whether totransmit an electrical signal indicative of an alarm condition using thesurface-contact detection device. Determining whether to transmit anelectrical signal indicative of an alarm condition may further includethe step of monitoring whether a radiating portion of an energyapplicator is disposed in contact with target tissue based on adetermination of whether optical signals generated the at least oneoptical transmitter result in reflected optical signals received at theat least one optical receiver. Determining whether to transmit anelectrical signal indicative of an alarm condition may further includethe step of causing cessation of energy delivery from theelectrosurgical power generating source through the radiating portion tothe target tissue if it is determined that optical signals generated bythe at least one optical transmitter do not result in reflected opticalsignals received at the at least one optical receiver.

According to another aspect of the present disclosure, a method ofdirecting energy to tissue is provided. The method includes the initialstep of positioning an energy applicator for delivery of energy totarget tissue. The energy applicator is provided with a surface-contactdetection device. The energy applicator is operably associated with anelectrosurgical power generating source. The method also includes thesteps of transmitting energy from an electrosurgical power generatingsource through the energy applicator to the target tissue, monitoringwhether a radiating portion of the energy applicator is disposed incontact with the target tissue based on a determination of whetheroptical signals generated by one or more optical transmitters of thesurface-contact detection device associated with the energy applicatorresult in reflected optical signals received at one or more opticalreceivers of the surface-contact detection device and, if it isdetermined that optical signals generated by the one or more opticaltransmitters do not result in reflected optical signals received at theone or more optical receivers, cause cessation of energy delivery fromthe electrosurgical power generating source through the radiatingportion to the target tissue.

In any one of the aspects, the one or more optical receivers may bephotodiodes. In any one of the aspects, the one or more opticaltransmitters may be light-emitting diodes (LEDs).

Electromagnetic energy is generally classified by increasing energy ordecreasing wavelength into radio waves, microwaves, infrared, visiblelight, ultraviolet, X-rays and gamma-rays. As it is used in thisdescription, “microwave” generally refers to electromagnetic waves inthe frequency range of 300 megahertz (MHz) (3×10⁸ cycles/second) to 300gigahertz (GHz) (3×10¹¹ cycles/second). As it is used in thisdescription, “ablation procedure” generally refers to any ablationprocedure, such as microwave ablation, radio frequency (RF) ablation ormicrowave ablation-assisted resection. As it is used in thisdescription, “energy applicator” generally refers to any device that canbe used to transfer energy from a power generating source, such as amicrowave or RF electrosurgical generator, to tissue.

As it is used in this description, “transmission line” generally refersto any transmission medium that can be used for the propagation ofsignals from one point to another. A transmission line may be, forexample, a wire, a two-wire line, a coaxial wire, and/or a waveguide.Transmission lines such as microstrip, coplanar waveguide, stripline orcoaxial may also be considered to be waveguides. As it is used in thisdescription, “waveguide” generally refers to any linear structure thatconveys electromagnetic waves between its endpoints.

As it is used in this description, “length” may refer to electricallength or physical length. In general, electrical length is anexpression of the length of a transmission medium in terms of thewavelength of a signal propagating within the medium. Electrical lengthis normally expressed in terms of wavelength, radians or degrees. Forexample, electrical length may be expressed as a multiple orsub-multiple of the wavelength of an electromagnetic wave or electricalsignal propagating within a transmission medium. The wavelength may beexpressed in radians or in artificial units of angular measure, such asdegrees. The electric length of a transmission medium may be expressedas its physical length multiplied by the ratio of (a) the propagationtime of an electrical or electromagnetic signal through the medium to(b) the propagation time of an electromagnetic wave in free space over adistance equal to the physical length of the medium. The electricallength is in general different from the physical length. By the additionof an appropriate reactive element (capacitive or inductive), theelectrical length may be made significantly shorter or longer than thephysical length.

As it is used in this description, “switch” or “switches” generallyrefers to any electrical actuators, mechanical actuators,electro-mechanical actuators (rotatable actuators, pivotable actuators,toggle-like actuators, buttons, etc.), optical actuators, or anysuitable device that generally fulfills the purpose of connecting anddisconnecting electronic devices, or component thereof, instruments,equipment, transmission line or connections and appurtenances thereto,or software.

Light may be regarded as an electromagnetic wave that travels instraight lines (gravity and electromagnetic influences excepted) untilit is either reflected or refracted. Reflection of light occurs when thelight waves encounter a surface or other boundary that does not absorbthe energy of the radiation and bounces the waves away from the surface.Commonly, the incoming light wave is referred to as an incident(original) wave, and the wave that is bounced away from the surface istermed the reflected wave. As it is used in this description,“reflection coefficient” generally refers to a ratio of a reflected waveto an incident wave at a point of reflection. Refraction of light occurswhen a light wave travels from a medium with a given refractive index toa medium with another refractive index. As it is used in thisdescription, “refraction” generally refers to the change in direction ofa wave due to a change in its speed, as occurs when a wave passes fromone medium to another. As it is used in this description, “refractiveindex” generally refers to a measure of how much the speed of light isreduced inside a medium, compared to the speed of light in vacuum orair.

As it is used in this description, “light source” generally refers toall illumination sources including photo-luminescent sources,fluorescent sources, phosphorescence sources, lasers,electro-luminescent sources, such as electro-luminescent lamps, andlight-emitting diodes. As it is used in this description,“light-emitting diode” generally refers to any system that is capable ofreceiving an electrical signal and producing a color of light inresponse to the signal. Thus, “light-emitting diode”, as used herein,includes light-emitting diodes (LEDs) of all types, including whiteLEDs, infrared LEDs, ultraviolet LEDs, visible color LEDs,light-emitting polymers, semiconductor dies that produce light inresponse to current, organic LEDs, electro-luminescent strips, siliconbased structures that emit light, and other such systems. As it is usedin this description, “color” generally refers to any frequency ofelectromagnetic radiation, or combination of different frequencies,within the visible light spectrum, the infrared and ultraviolet areas ofthe spectrum, and in other areas of the electromagnetic spectrum whereillumination sources may generate radiation.

As it is used in this description, “optical receiver” generally refersto a device that converts an incoming optical signal to an electricalsignal. An optical receiver may include a transducer in the form of adetector, which may be a photodiode or other device. As it is used inthis description, “optical transmitter” generally refers to a devicethat outputs an optical signal, including devices that convert anelectrical signal into an optical signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Objects and features of the presently-disclosed systems, devices andmethods for optical detection of surface contact of an electrosurgicaldevice to tissue and the presently-disclosed electrosurgical devicesincluding a waveguide with removable dielectric structures will becomeapparent to those of ordinary skill in the art when descriptions ofvarious embodiments thereof are read with reference to the accompanyingdrawings, of which:

FIG. 1 is a schematic diagram of an electrosurgical system including anenergy applicator provided with a surface-contact detection device inaccordance with an embodiment of the present disclosure;

FIG. 2 is an enlarged, cross-sectional view of an embodiment of theenergy applicator and the surface-contact detection device shown in FIG.1, with parts separated, in accordance with the present disclosure;

FIG. 3 is an enlarged, cross-sectional view of the assembled energyapplicator of FIG. 2 shown in a configuration with the surface-contactdetection device of FIG. 2 coupled to a distal end portion thereof inaccordance with an embodiment of the present disclosure;

FIG. 4 is an enlarged, cross-sectional view of another embodiment of theenergy applicator and the surface-contact detection device shown in FIG.1, with parts separated, in accordance with the present disclosure;

FIG. 5 is an enlarged, cross-sectional view of the assembled energyapplicator of FIG. 4 shown in a configuration with the surface-contactdetection device of FIG. 4 coupled to a distal end portion thereof inaccordance with an embodiment of the present disclosure;

FIG. 6 is an enlarged, cross-sectional view of the surface-contactdetection device shown in FIG. 1 in accordance with an embodiment of thepresent disclosure;

FIG. 7 is an enlarged, cross-sectional view taken along the section lineI-I of FIG. 6;

FIG. 8 is an enlarged, perspective view of a portion of an energyapplicator and a surface-contact detection device coupled thereto inaccordance with an embodiment of the present disclosure;

FIG. 9 is an enlarged, perspective view of a portion of an energyapplicator and a surface-contact detection device coupled thereto inaccordance with another embodiment of the present disclosure;

FIG. 10 is a diagrammatic representation of a radiation pattern ofelectromagnetic energy delivered into tissue by an energy applicator,such as the energy applicator of FIG. 1, in accordance with anembodiment of the present disclosure;

FIG. 11A is an enlarged, schematic view of a portion of asurface-contact detection device, such as the surface-contact detectiondevice of FIG. 8, shown in a first configuration in which the lensmember is disposed in spaced relation to tissue, wherein the opticaltransmitter and the optical receiver do not communicate, in accordancewith an embodiment of the present disclosure;

FIG. 11B is an enlarged, schematic view of a portion of asurface-contact detection device, such as the surface-contact detectiondevice of FIG. 8, shown in a second configuration in which the lensmember is disposed in contact with tissue, wherein the opticaltransmitter and the optical receiver communicate, in accordance with anembodiment of the present disclosure;

FIG. 12 is an enlarged, perspective view of an energy applicator, suchas the energy applicator of FIG. 1, shown positioned for delivery ofenergy to tissue in accordance with an embodiment of the presentdisclosure;

FIG. 13 is a schematic diagram of a portion of a surface-contactdetection device shown with a first portion of the lens member disposedin contact with tissue, wherein the optical transmitters and the opticalreceivers associated with the first portion communicate, in accordancewith an embodiment of the present disclosure;

FIG. 14 is a schematic diagram of an energy applicator that includes anantenna assembly including a waveguide with removable dielectricstructures, shown with the surface-contact detection device of FIG. 8,with parts separated, in accordance with an embodiment of the presentdisclosure;

FIG. 15 is a schematic diagram of another embodiment of an energyapplicator that includes an antenna assembly including a waveguide withremovable dielectric structures, shown with the surface-contactdetection device of FIG. 8, with parts separated, in accordance with anof the present disclosure;

FIG. 16 is a schematic diagram of yet another embodiment of an energyapplicator that includes an antenna assembly including a waveguide withremovable dielectric structures, shown with the surface-contactdetection device of FIG. 8, with parts separated, in accordance with anof the present disclosure;

FIG. 17 is a schematic diagram of still another embodiment of an energyapplicator that includes an antenna assembly including a waveguide withremovable dielectric structures, shown with the surface-contactdetection device of FIG. 8, with parts separated, in accordance with anof the present disclosure;

FIG. 18 is a schematic diagram of still another embodiment of an energyapplicator that includes an antenna assembly including a waveguide withremovable dielectric structures, with parts separated, in accordancewith an of the present disclosure;

FIG. 19 is a flowchart illustrating a method of directing energy totissue in accordance with an embodiment of the present disclosure;

FIG. 20 is a flowchart illustrating an embodiment of the step ofdetermining whether to transmit an electrical signal indicative of analarm condition of the method illustrated in FIG. 19 in accordance withthe present disclosure; and

FIG. 21 is a flowchart illustrating a method of directing energy totissue in accordance with another embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments of the presently-disclosed systems, devices andmethods for optical detection of surface contact of an electrosurgicaldevice to tissue and embodiments of the presently-disclosedelectrosurgical devices including a waveguide with removable dielectricstructures are described with reference to the accompanying drawings.Like reference numerals may refer to similar or identical elementsthroughout the description of the figures. As shown in the drawings andas used in this description, and as is traditional when referring torelative positioning on an object, the term “proximal” refers to thatportion of the device, or component thereof, closer to the user and theterm “distal” refers to that portion of the device, or componentthereof, farther from the user.

This description may use the phrases “in an embodiment,” “inembodiments,” “in some embodiments,” or “in other embodiments,” whichmay each refer to one or more of the same or different embodiments inaccordance with the present disclosure.

Various embodiments of the present disclosure provide electrosurgicaldevices for treating tissue. Various embodiments of the presentdisclosure provide systems, devices and methods for optical detection ofsurface-to-surface contact between an electrosurgical device surface andtissue. Embodiments may be implemented using electromagnetic radiationat microwave frequencies or at other frequencies. An electrosurgicalsystem including an energy applicator including a surface-contactdetection device, according to various embodiments, is configured tooperate between about 300 MHz and about 10 GHz.

Various embodiments of the presently-disclosed electrosurgical systemsincluding an energy applicator provided with a surface-contact detectiondevice are suitable for microwave ablation and for use to pre-coagulatetissue for microwave ablation assisted surgical resection.

FIG. 1 shows an electrosurgical system (shown generally as 10) includingan energy applicator 100. Energy applicator 100 includes an antennaassembly (shown generally as 280 in FIGS. 2 and 3), which is describedin more detail later in this description, and a handle member 150including a housing 151. A transmission line 15 may be provided toelectrically couple the energy applicator 100 to an electrosurgicalpower generating source 28, e.g., a microwave or radio frequency (RF)electrosurgical generator. In some embodiments, as shown in FIG. 1, theenergy applicator 100 is coupled via the transmission line 15 to aconnector 16, which further operably connects the energy applicator 100to the electrosurgical power generating source 28. Power generatingsource 28 may be any generator suitable for use with electrosurgicaldevices and may be configured to provide various frequencies of energy.

In some embodiments, the energy applicator 100 may be configured to becoupleable with a surface-contact detection device (e.g.,surface-contact detection device 130 shown in FIGS. 2, 3, 6 and 7,surface-contact detection device 830 shown in FIG. 8, andsurface-contact detection device 930 shown in FIG. 9). Surface-contactdetection device 130 may include one or more connector portions (notshown) provided with one or more electrical connectors or terminalssuitable for making electrical connections with certain of the circuitryof the handle member 150.

An embodiment of an energy applicator, such as the energy applicator 100of the electrosurgical system 10 shown in FIG. 1, in accordance with thepresent disclosure, is shown in more detail in FIGS. 2 and 3. It will beunderstood, however, that other energy applicator embodiments (e.g.,energy applicator 400 shown in FIGS. 4 and 5, and energy applicators1400, 1500, 1600, 1700 and 1800 shown in FIGS. 14, 15, 16, 17 and 18,respectively) may also be used.

Housing 151 includes a grip portion 153 adapted to be gripped by theuser, and may be formed of any suitable material, e.g., ceramic orpolymeric materials. Grip portion 153 may have any suitable shape andmay be provided with an ergonomic surface which is configured to becomfortably gripped by the hand of the user during operation of theinstrument. In some embodiments, the energy applicator 100 may beadapted to be a reusable device. Autoclavable materials may be used toform the housing 151, and/or other components of the energy applicator100, to provide for a sterilizable device.

Energy applicator 100 may include a user interface 160 associated withthe housing 151. In some embodiments, as shown in FIGS. 1, 2 and 4, theuser interface 160 is disposed near the distal end 159 of the handlemember 150. User interface 160 may include one or more controls 161 thatmay include without limitation a switch (e.g., pushbutton switch, toggleswitch, slide switch) and/or a continuous actuator (e.g., rotary orlinear potentiometer, rotary or linear encoder), and may have a desiredergonomic form. User interface 160 may be adapted to enable a user toselectively configure one or more operating parameters associated withthe device, or component thereof, e.g., depending upon a particularpurpose and/or to achieve a desired surgical outcome. User interface 160may include an indicator unit (not shown) adapted to provide audioand/or other perceptible sensory alerts It is to be understood that theuser interface 160 may be disposed at another location on the housing151.

Based on one or more electrical signals generated by the user interface160, a controller (not shown) and/or other circuitry (not shown) mayadjust one or more operating parameters associated with the powergenerating source 28 and/or perform other control functions, alarmingfunctions, or other functions in association therewith. The controllermay be disposed within the power generating source 28, or located at thehandle member 150 of the energy applicator 100. The controller may be astandalone unit. Some examples of operating parameters associated withthe power generating source 28 that may be adjusted include temperature,impedance, power, current, voltage, mode of operation, and duration ofapplication of electromagnetic energy.

In some embodiments, the housing 151 is formed from two housing halves(not shown). Each half of the housing 151 may include a series ofmechanical interfacing components (not shown) configured to matinglyengage with a corresponding series of mechanical interfaces (not shown)to align the two housing halves about the inner components andassemblies of the energy applicator 100. It is contemplated that thehousing halves (as well as other components described herein) may beassembled together with the aid of alignment pins, snap-like interfaces,tongue and groove interfaces, locking tabs, adhesive ports, etc.,utilized either alone or in combination for assembly purposes.

In some embodiments, as shown in FIGS. 1-5, the housing 151 includes aneck portion 156, e.g., disposed at the proximal end 157 of the handlemember 150. Neck portion 156 defines an aperture therethrough configuredto receive a portion of the transmission line 15 therein, and may beformed of any suitable material. Neck portion 156 may be formed of arigid material and/or structurally reinforced with suitably rigidmaterial, e.g., to enhance the reliability of the connection between theantenna assembly 280 and the transmission line 15. The shape and size ofthe neck portion 156 may be varied from the configuration depicted inFIGS. 1-5.

Housing 151 may be adapted to provide various configurations ofelectrical connections between the user interface 160, or componentthereof (e.g., one or more controls 161), and one or more conductors forcommunicating control, feedback and/or identification signals betweenthe energy applicator 100 and the power generating source 28. It is tobe understood that the dotted lines indicative of electrical connections(e.g., electrical conductors) between various components of the energyapplicator 100 shown in FIGS. 2-5 are merely illustrative andnon-limiting examples of electrical connections, and that medical deviceembodiments of the present disclosure may utilize many differentconfigurations of electrical connections, some with fewer, oradditional, electrical connections than depicted in FIGS. 2-5. In someembodiments, a cable harness or the like may be disposed within thehandle member 150, e.g., to allow communication between the detectiondevice 130 and the user interface 160, or component thereof (e.g., oneor more controls 161), and may be coupled via a cable bundle, e.g.,disposed within the transmission line 15, to the power generating source28.

Transmission line 15 includes an inner conductor 210 and an outerconductor 260, and may include a dielectric material 240 separating theinner conductor 210 and the outer conductor 260. In some embodiments,the inner conductor 210 is formed from a first electrically-conductivematerial (e.g., stainless steel) and the outer conductor 260 is formedfrom a second electrically-conductive material (e.g., copper). Innerconductor 210 and the outer conductor 260 may be formed from anysuitable electrically-conductive material. Transmission line 15 may becooled by fluid, e.g., saline or water, to improve power handling.Transmission line 15 may additionally, or alternatively, provide aconduit (not shown) configured to provide coolant from a coolant source48 for cooling or buffering the energy applicator 100, e.g., deionizedwater, or other suitable cooling medium.

As shown in FIG. 3, the energy applicator 100 includes an antennaassembly 280 having a radiating portion 112. Referring to FIG. 2, theantenna assembly 280 includes a waveguide 285 with an open end 283 and awaveguide feed structure 282 having a coaxial line, e.g., distal portionof a coaxial line within the transmission line 15. Waveguide 285includes electrically-conductive walls 284 of generally tubular shape,e.g., having a circular or rectangular cross section, and may be hollowor filled with a dielectric material. In some embodiments, the waveguide285 may filled with a dielectric structure, e.g., a stack including twoor more layers of dielectric material.

The waveguide walls 284 define a cavity 286 therein, and may include anyelectrically-conductive material, such as, for example, copper,stainless steel, titanium, titanium alloys such as nickel-titanium andtitanium-aluminum-vanadium alloys, aluminum, aluminum alloys, tungstencarbide alloys, or combinations thereof. A portion 211 of the innerconductor 210 extends within the cavity 286. The cavity 286 is filledwith a dielectric structure (shown generally as 290 in FIGS. 2 and 3).In some embodiments, the inner conductor 210 may terminate on the cavitywall. As seen in FIG. 2, the dielectric structure 290 includes a firstdielectric layer 291 of length “L1”, a second dielectric layer 292 oflength “L2”, and a third dielectric layer 293 of length “L3”. The innerconductor 210 may terminate within any one of the first, second, orthird dielectric layers 291, 292, or 293, respectively. The number,shape and length of the dielectric layers of the dielectric structure290 (referred to hereinafter as the first dielectric structure 290) maybe varied from the configuration depicted in FIGS. 2 and 3.

In some embodiments, as shown in FIGS. 2 and 3, a portion of the firstdielectric structure 290 extends outwardly from the open end 283 of thewaveguide 285. In other embodiments, the first dielectric structure(e.g., first dielectric structure 490 shown in FIGS. 4 and 5) isdisposed entirely within the cavity 286 defined by the waveguide walls284. The dielectric materials used to form the first dielectricstructure 290 may vary in dielectric constant, e.g., to aid in radiationdirectivity and impedance matching and/or to achieve the optimum energyto tissue delivery. In some embodiments, the waveguide feed structure282 may include a coaxial line to waveguide adapter (not shown), such aswithout limitation female and male type “N” or SMA connectors, or otherelectrical connector, which may be at least partially disposed withinthe neck portion 156 of the housing 151. In some embodiments, as shownin FIG. 2, a distal portion 294 of the third dielectric layer 293extends outwardly from the open end 283 of the waveguide 285.

Energy applicator 100 may include a second dielectric structure disposedin proximity to the distal end 159 of the handle member 150, inassociation with the first dielectric structure 290. In someembodiments, as shown in FIGS. 2 and 3, the energy applicator 100includes a second dielectric structure 120 of length “L4” configured tobe coupleable with the distal end 294 (FIG. 2) of the third dielectriclayer 293 of the first dielectric structure 290. Second dielectricstructure 120 has a generally dome-like shape, but other configurationsmay be utilized, e.g., depending on the procedure to be performed,tissue characteristics of the target tissue or of the tissues adjacentthereto, etc. In some embodiments, the first dielectric structure 290and the second dielectric structure 120 are configured to match theimpedance of the transmission line 15 to the impedance of the targettissue.

During microwave ablation, e.g., using the electrosurgical system 10,the energy applicator 100 is inserted into or placed adjacent to tissueand microwave energy is supplied thereto. FIG. 10 diagrammaticallyillustrates a radiation pattern of electromagnetic energy delivered intotissue by an energy applicator, such as the energy applicator 100 ofFIG. 1. A clinician may pre-determine the length of time that microwaveenergy is to be applied. The duration of microwave energy applicationusing the energy applicator 100 may depend on the progress of the heatdistribution within the tissue area that is to be destroyed and/or thesurrounding tissue. Electrosurgical system 10 may be adapted to causecessation of energy delivery from the electrosurgical power generatingsource 28 through the radiating portion 112 of the energy applicator 100to the target tissue based on an electrical signal transmitted by thesurface-contact detection device 130, e.g., indicative of an alarmcondition.

In operation, microwave energy having a wavelength, lambda (λ), istransmitted through the antenna assembly 280, e.g., along the waveguide285, the first dielectric structure 290 and/or the second dielectricstructure 120, and radiated into the surrounding medium, e.g., tissue.The length of the antenna for efficient radiation may be dependent onthe effective wavelength, λ_(eff), which is dependent upon thedielectric properties of the medium being radiated into. Antennaassembly 280 through which microwave energy is transmitted at awavelength, λ, may have differing effective wavelengths, λ_(eff),depending upon the surrounding medium, e.g., liver tissue, as opposed tobreast tissue.

In some embodiments, the second dielectric structure 120 of FIGS. 2, 3and 14-17 (and/or the second dielectric structure 420 shown in FIGS. 4and 5) may be configured to be selectively detachable and/or removeablyreplaced, e.g., to allow selective matching of the impedance of thetransmission line 15 to the impedance of a particular type or tissue.One or more dielectric layers of the first dielectric structure (e.g.,the third dielectric layer 1493 of the first dielectric structure 1490shown in FIG. 14, the second and/or third dielectric layers 1592 and/or1593 of the first dielectric structure 1590 shown in FIG. 15, the thirddielectric layer 1693 of the first dielectric structure 1690 shown inFIG. 16, and the second and third dielectric layers 1792 and 1793 of thefirst dielectric structure 1790 shown in FIG. 17) may additionally, oralternatively, be multi-configuration modular structures, and may beconfigured to be selectively removeably positioned/replaced, e.g., toallow selective matching of the impedance of the transmission line 15 tothe impedance of a particular type or tissue.

A surface-contact detection device in accordance with embodiments of thepresent disclosure (e.g., surface-contact detection device 130 shown inFIGS. 2, 3, 6 and 7, surface-contact detection device 830 shown in FIG.8, and surface-contact detection device 930 shown in FIG. 9) may beadapted for use with the energy applicator 100, and may be coupled,secured, or releaseably secured to the distal end 159 of the handlemember 150 and/or the distal end of the waveguide walls 284.

Surface-contact detection device 130 has a generally ring-likeconfiguration defined by a body member 237 and a lens member 233 andincluding a central opening 609 (FIGS. 6 and 7), e.g., configured toreceive at least a portion of the distal portion 294 of the thirddielectric layer 293 therein. In some embodiments, as shown in FIGS. 2and 4, the body member 237 includes a first body element 235 and asecond body element 236, which are coupled together and define aninternal cavity 239. First body element 235 may be configured to engagethe distal end 159 of the handle member 150 and/or the distal end of thewaveguide walls 284. As seen in FIG. 6, the first body element 235includes an inner surface 238, and the second body element 236 generallydefines the central opening 609.

Body member 237, or portions thereof, may be coupled, secured, orreleaseably secured to the distal end 159 of the handle member 150(and/or the distal portion 294 of the third dielectric layer 293) usingany suitable fastener mechanism, such as adhesive, mechanicalinterfacing components, etc. In some embodiments, the first body element235 and the distal end 159 of the handle member 150 are bonded orotherwise joined together using an adhesive material 244, and/or thesecond body element 236 and the lateral surface of the distal portion294 of the third dielectric layer 293 are bonded or otherwise joinedtogether using an adhesive material 246. In alternative embodiments notshown, the surface-contact detection device 130 may be adapted to beremoveably coupleable (e.g., threadedly coupleable) to the distalportion 294 of the third dielectric layer 293 that extends outwardlyfrom the open end 283 of the waveguide 285 and/or removeably coupleableto the dielectric structure 120 or portion thereof.

Surface-contact detection device 130 generally includes one or morelight source or light-emitting elements 275 (also referred to herein asoptical transmitters 275) and one or more light-receiving elements 277(also referred to herein as optical receivers 277). In variousembodiments, one or more optical transmitters 275 may be coupled to thefirst body element 235 (and/or the second body element 236), and one ormore optical receivers 277 may be coupled to the second body element 236(and/or the first body element 235). Optical transmitters 275 may be anylight source or suitable device configured to transmit optical signals,e.g., a light-emitting diode (LED) 276. LED 276 may be configured totransmit either a continuous or pulsed optical signal. Optical receivers277 may include any suitable device configured to receive opticalsignals, e.g., a photo-diode 278. In various embodiments, at least oneoptical transmitter 275 and at least one optical receiver 277 areconfigured to communicate when the lens member 233 is disposed inintimate contact with tissue.

Energy applicator 100 may include one or more electrical conductorsassociated with the handle member 150 (and/or housing 151) for providingone or more electrically-conductive pathways. Surface-contact detectiondevice 130 may include one or more connector portions provided with oneor more electrical connectors or terminals suitable for makingelectrical connections with electrical conductors associated with thehandle member 150 (and/or housing 151). The one or more connectorportions may be configured to be removeably coupleable to electricalconductors associated with the handle member 150 (and/or housing 151).

Lens member 233 may be configured as a single pane (also referred toherein as a “lens element”) or a plurality of panes, and may be formedof any suitable transparent or translucent material. In someembodiments, the lens member 233 may be formed of transparent ortranslucent material that by its material characteristics is reflectiveto optical signals transmitted by the optical transmitter 275 (e.g.,emitted LED wavelength) when the lens member 233 is disposed in intimatecontact with tissue, and transparent to the optical signals when thereis no contact between the lens member 233 and tissue. In otherembodiments, material suitable for forming the lens member 233 hasmaterial characteristics whereby the lens member 233 is transparent tooptical signals transmitted by the optical transmitter 275 (e.g.,emitted LED wavelength) when the lens member 233 is disposed in intimatecontact with tissue, and reflective to the optical signals in theabsence of contact between the lens member 233 and tissue.

Lens member 233 may include one or more lens elements of various shapesincluding flat and/or curved surfaces. Lens member 233 may include oneor more lens elements, e.g., first lens element 231 and second lenselement 232, having the same or different opacity. First lens element231 and the second lens element 232 may be integrally formed as part ofa unitary structure, if desired, or formed separately and joinedtogether by any suitable process.

As best seen in FIG. 7, the surface-contact detection device 130includes a plurality of optical transmitters 275 (e.g., LEDs 276) and aplurality of optical transmitters 275 (e.g., photodiodes 278), whereineach respective optical transmitter 275 is individually paired with adifferent one of the optical receivers 277. Although the surface-contactdetection device 130 shown in FIG. 7 is configured to include sixteenoptical transmitter-receiver pairs 279, any suitable configuration ofoptical transmitters 275 and optical receivers 277 may be used. In someembodiments, a plurality of optical transmitters (e.g., first opticaltransmitter 978 and second optical transmitter 979 shown in FIG. 9) maybe associated each optical receiver 277.

Each optical transmitter-receiver pair 279 includes an opticaltransmitter 275 (e.g., LED 276) disposed in a positional relation to thefirst lens element 231 so that optical signals transmitted by theoptical transmitter 275 impinge on the first lens element 231. In someembodiments, the optical signals transmitted by each respective opticaltransmitter 275 are either, reflected by the first lens element 231 andimpinge on an optical receiver 277, or not reflected by the first lenselement 231 and do not impinge on the optical receiver 277, depending onwhether the outer surface 234 of the first lens element 231 is disposedin intimate contact with tissue. When the lens member 233 is disposed inintimate contact with tissue, the first lens element 231 reflectsoptical signals transmitted by the optical transmitters 275 towards theoptical receivers 277.

In some embodiments, the absence of optical signals incident on each andevery optical receiver 277 is interpreted as indicative that the distalradiating portion 112 of the energy applicator 100 is not disposed incontact with tissue. There may be circumstances wherein a first portionof a lens member (e.g., lens member 833 shown in FIG. 8) is disposed incontact with tissue “T” and a second portion is disposed in spacedrelation to tissue “T”, such as shown in FIG. 13, wherein the one ormore optical transmitters 275 and optical receivers 277 associated withthe first portion communicate, and the one or more optical transmitters275 and optical receivers 277 associated with the second portion do notcommunicate. In some embodiments, the absence of optical signalsincident on a predetermined number (or a number within a predeterminedrange) of the optical receivers 277 (e.g., all optical receivers 277except for one or two) is interpreted as indicative that the distalradiating portion 112 of the energy applicator 100 is not disposed incontact with tissue.

In some embodiments, when the desired number of the optical receivers277 have detected optical signals, the surface-contact detection device130 transmits an electrical signal to an electrosurgical powergenerating source (e.g., electrosurgical power generating source 28shown in FIG. 1) and, in response thereto, the power output of the powergenerating source may be reduced, e.g., for a predetermined timeinterval or until a manual reset switch is actuated.

In some embodiments, the presently-disclosed surface-contact detectiondevices may additionally include one or more sensors (not shown), suchas without limitation, a temperature sensor, a power sensor to monitorforward and/or reflected power, and/or a radiation detector.

FIG. 8 shows a portion of an energy applicator (shown generally as 800)that includes a handle member 850 including a housing 851. Handle member850 and the housing 851 are similar to the handle member 150 and thehousing 151 shown in FIGS. 1-5 and further description thereof isomitted in the interests of brevity. In some embodiments, the energyapplicator 800 includes a waveguide (e.g., waveguide 285 shown in FIGS.2-5, or any one of the waveguides 1485, 1585, 1685 and 1785 shown inFIGS. 14, 15, 16 and 17, respectively), and may include a firstdielectric structure (e.g., first dielectric structure 290 shown inFIGS. 2 and 3, first dielectric structure 490 shown in FIGS. 4 and 5, orany one of first dielectric structures 1490, 1590, 1690 and 1790 shownin FIGS. 14, 15, 16 and 17, respectively). Although the energyapplicator 800 shown in FIG. 8 is provided with the second dielectricstructure 120, other configurations may be utilized (e.g., seconddielectric structure 420 shown in FIGS. 4 and 5).

Energy applicator 800 is provided with a surface-contact detectiondevice 830 which may be coupled, secured, or releaseably secured to thedistal end of the handle member 850 and/or the distal end of waveguidewalls (e.g., waveguide walls 284 shown in FIGS. 2-5). Surface-contactdetection device 830 may be provided with a configuration of one or moreof electrical connectors for making electrical connections with one ormore electrical connectors of the handle member 850 and/or othercomponents of the energy applicator 800. Surface-contact detectiondevice 830 includes a lens member 833, which may be formed of anysuitable transparent or translucent material. Lens member 833 is similarto the lens member 233 shown in FIGS. 2-7 and further descriptionthereof is omitted in the interests of brevity.

Surface-contact detection device 830 is similar to the surface-contactdetection device 130 shown in FIGS. 1-7, except for the configuration ofthe optical transmitters 275 and the optical receivers 277.Surface-contact detection device 830 generally includes a plurality ofoptical transmitters 275 and a plurality of optical receivers 277,wherein each respective optical transmitter 275 is individually pairedwith a different one of the optical receivers 277. As seen in FIG. 8,the pairs 273 of optical transmitters 275 and the optical receivers 277of the surface-contact detection device 830 are disposed in spaced apartrelation to one another in a ring-like configuration, and may bedisposed on a single surface (e.g., inner surface 238 of first bodyelement 235 shown in FIG. 6).

FIG. 9 shows a portion of an energy applicator (shown generally as 900)that includes a handle member 950 including a housing 951. Handle member950 and the housing 951 are similar to the handle member 150 and thehousing 151 shown in FIGS. 1-5 and further description thereof isomitted in the interests of brevity. Energy applicator 900 may include awaveguide (e.g., waveguide 285 shown in FIGS. 2-5, or waveguides 1485,1585, 1685 and 1785 shown in FIGS. 14, 15, 16 and 17, respectively), andmay include a first dielectric structure (e.g., first dielectricstructure 290 shown in FIGS. 2 and 3, first dielectric structure 490shown in FIGS. 4 and 5, or first dielectric structure 1490, 1590, 1690and 1790 shown in FIGS. 14, 15, 16 and 17, respectively) and/or thesecond dielectric structure 120.

Energy applicator 900 is provided with a surface-contact detectiondevice 830. Surface-contact detection device 830 is adapted for use withthe energy applicator 800, e.g., provided with a configuration of one ormore electrical connectors for making electrical connections with one ormore electrical connectors of the energy applicator 800, and may becoupled, secured, or releaseably secured to the distal end of the handlemember 150 and/or the distal end of the waveguide walls (not shown).Surface-contact detection device 930 includes a lens member 933, whichmay be formed of any suitable transparent or translucent material. Lensmember 933 is similar to the lens member 233 shown in FIGS. 2-7 andfurther description thereof is omitted in the interests of brevity.

Surface-contact detection device 930 is similar to the surface-contactdetection device 830 shown in FIG. 8, except that the surface-contactdetection device 930 includes two optical transmitters (also referred toherein as the first optical transmitter 978 and the second opticaltransmitters 979) disposed in association with each optical receiver277, as opposed to the one-to-one correspondence of optical transmitters275 and optical receivers 277 of the surface-contact detection device830 shown in FIG. 8.

FIG. 10 diagrammatically illustrates a radiation pattern ofelectromagnetic energy delivered into tissue “T” by an energyapplicator, such as the energy applicator 100 shown in FIGS. 1 and 12,in accordance with an embodiment of the present disclosure.

FIG. 11A shows a portion of a surface-contact detection device (e.g.,surface-contact detection device 830 shown in FIG. 8) disposed in afirst configuration, wherein the lens member 833 is positioned in spacedrelation to tissue “T”. In this configuration, the optical signalstransmitted by the optical transmitter 275 (e.g., LED 276) pass throughthe lens member 833. As a result, the optical transmitter 275 and theoptical receiver 277 (e.g., photodiode 278) do not communicate.

In FIG. 11B, the portion of the surface-contact detection device of FIG.11A is shown disposed in a second configuration, wherein the lens member833 is disposed in contact with tissue “T”. In this configuration, theoptical signals transmitted by the optical transmitter 275 (e.g., LED276) are reflected by the lens member 833 and impinge upon the opticalreceiver 277 (e.g., photodiode 278). As a result, the opticaltransmitter 275 and the optical receiver 277 communicate.

FIG. 12 shows an energy applicator, such as the energy applicator 100shown in FIG. 1, positioned for energy delivery into tissue “T”.Electrosurgical systems in accordance with the present disclosure may beadapted to deliver energy from an electrosurgical power generatingsource 28 to the energy applicator 100 and/or to cause cessation ofenergy delivery from the electrosurgical power generating source 28through the radiating portion 112 of the energy applicator 100 to tissue“T” based on one or more electrical signals transmitted by asurface-contact detection device (e.g., surface-contact detection device130 shown in FIGS. 2, 3, 6 and 7, surface-contact detection device 830shown in FIG. 8, or surface-contact detection device 930 shown in FIG.9).

The various energy applicator embodiments shown in FIGS. 14-17 generallyinclude an antenna assembly including a waveguide with removabledielectric structures, and may be configured to be coupleable with asurface-contact detection device (e.g., surface-contact detection device130 shown in FIGS. 2, 3, 6 and 7, surface-contact detection device 830shown in FIG. 8, or surface-contact detection device 930 shown in FIG.9). The energy applicators 1400, 1500, 1600, 1700 and 1800 shown inFIGS. 14, 15, 16, 17 and 18, respectively, which are described in moredetail below, may include any of the components of the energy applicator100 shown in FIGS. 1-3.

FIG. 14 shows an energy applicator (shown generally as 1400) inaccordance with an embodiment of the present disclosure that includes anantenna assembly 1480 including a waveguide 1485 with removabledielectric structures. Energy applicator 1400 includes a handle member1450, and may include a user interface 160, e.g., disposed near thedistal end of the handle member 1450. Handle member 1450 includes ahousing 1451 including a threaded portion 1452. Handle member 1450 andthe housing 1451 are similar to the handle member 150 and the housing151, respectively, shown in FIGS. 1-3, except for the threaded portion1452 of the housing 1451 shown in FIG. 14, and further descriptionthereof is omitted in the interests of brevity.

Waveguide 1485 includes electrically-conductive walls 1484 a, 1484 b ofgenerally tubular shape. The electrically-conductive walls 1484 bincluding a threaded portion 1488 are separable from the housing 1451.The waveguide walls 1484 a, 1484 b define a cavity 1486 therein, and maybe formed of any electrically-conductive material, such as withoutlimitation, copper, stainless steel, titanium, titanium alloys such asnickel-titanium and titanium-aluminum-vanadium alloys, aluminum,aluminum alloys, tungsten carbide alloys, or combinations thereof.

The cavity 1486 is filled with a dielectric structure (shown generallyas 1490, with parts separated, in FIG. 14) including a first dielectriclayer 1491, a second dielectric layer 1492, and a third dielectric layer1493. The dielectric materials used to form the first dielectricstructure 1490 may vary in dielectric constant, e.g., to aid inradiation directivity and impedance matching and/or to achieve theoptimum energy to tissue delivery. The shape, size and number ofdielectric layers of the dielectric structure 1490 (referred tohereinafter as the first dielectric structure 1490) may be varied fromthe configuration depicted in FIG. 14.

As seen in FIG. 14, the third dielectric layer 1493 disposed inassociation with the electrically-conductive walls 1484 b is configuredto be separable from the housing 1451, e.g., to allow for the removaland replacement thereof. This provides the flexibility to modularlyadapt and reconfigure the antenna assembly 1480, as desired, e.g., tomatch the impedance of the transmission line 15 to the impedance oftissue.

In some embodiments, the length of the threaded portion 1488 associatedwith the electrically-conductive walls 1484 b is less than the length ofthe third dielectric layer 1493, e.g., to provide a space of adequatelength “L5” to accommodate the surface-contact detection device 830having height “H”. Surface-contact detection device 830 may be coupled,secured, or releaseably secured to the distal end portion 1494 of thethird dielectric layer 1493 and/or the distal end of the waveguide walls1484 b.

In some embodiments, as shown in FIG. 14, the energy applicator 1400includes a second dielectric structure 1420 configured to be coupleablewith the distal end portion 1494 of the first dielectric structure 1490.In other embodiments, a second dielectric structure (e.g., seconddielectric structure 1820 shown in FIG. 18) may be configured to becoupleable with the distal end of the first dielectric structure and/orthe distal end of the waveguide walls. Second dielectric structure 1420has a generally dome-like shape, but other configurations may beutilized, e.g., depending on the procedure to be performed, tissuecharacteristics of the target tissue or of the tissues adjacent thereto,etc. Second dielectric structure 1420 is similar to the seconddielectric structure 120 shown in FIGS. 1-3 and further descriptionthereof is omitted in the interests of brevity.

FIG. 15 shows an energy applicator (shown generally as 1500) inaccordance with an embodiment of the present disclosure that includes anantenna assembly 1580 including a waveguide 1585 with removabledielectric structures. Energy applicator 1500 includes a handle member1550, and may include a user interface 160 disposed in association withthe handle member 1550. Handle member 1550 includes a housing 1551including a threaded portion 1552. Handle member 1550 and the housing1551 are similar to the handle member 150 and the housing 151,respectively, shown in FIGS. 1-3, except for the threaded portion 1552of the housing 1551 shown in FIG. 15, and further description thereof isomitted in the interests of brevity.

Waveguide 1585 includes electrically-conductive walls 1584 a, 1584 b and1584 c of generally tubular shape. The electrically-conductive walls1584 b including a first threaded portion 1588, and theelectrically-conductive walls 1584 c including a second threaded portion1589 are individually separable from the housing 1551. The waveguidewalls 1584 a, 1584 b and 1584 c define a cavity 1586 therein, and may beformed of any suitable electrically-conductive material.

The cavity 1586 is filled with a dielectric structure (shown generallyas 1590, with parts separated, in FIG. 15) including a first dielectriclayer 1591, a second dielectric layer 1592, and a third dielectric layer1593. The dielectric materials used to form the first dielectricstructure 1590 may vary in dielectric constant, e.g., to aid inradiation directivity and impedance matching and/or to achieve theoptimum energy to tissue delivery. The shape, size and number ofdielectric layers of the dielectric structure 1590 (referred tohereinafter as the first dielectric structure 1590) may be varied fromthe configuration depicted in FIG. 15.

As seen in FIG. 15, the second and third dielectric layers 1592 and 1593disposed in association with the electrically-conductive walls 1584 band 1584 c, respectively, are configured to be separable from thehousing 1551, e.g., to allow for the removal and replacement thereof.This provides the flexibility to modularly adapt and reconfigure theantenna assembly 1580, as desired, e.g., to match the impedance of thetransmission line 15 to the impedance of tissue.

In some embodiments, as shown in FIG. 15, the energy applicator 1500includes a second dielectric structure 1520 coupled to the distal end ofthe third dielectric layer 1593 of the first dielectric structure 1590.Second dielectric structure 1520 is similar to the second dielectricstructure 120 shown in FIGS. 1-3 and further description thereof isomitted in the interests of brevity.

FIG. 16 shows an energy applicator (shown generally as 1600) inaccordance with an embodiment of the present disclosure that includes anantenna assembly 1680 including a waveguide 1685 with removabledielectric structures. Energy applicator 1600 includes a handle member1650 including a housing 1651, which are similar to the handle member150 and the housing 151, respectively, shown in FIGS. 1-3 and furtherdescription thereof is omitted in the interests of brevity. Energyapplicator 1600 may include a user interface 160 disposed in associationwith the handle member 1650.

Waveguide 1685 includes electrically-conductive walls 1684 of generallytubular shape, and may be formed of any suitable electrically-conductivematerial. The waveguide walls 1684 define a cavity 1686 therein andinclude a threaded portion 1652. The cavity 1686 is filled with adielectric structure (shown generally as 1690, with parts separated, inFIG. 16) including a first dielectric layer 1691, a second dielectriclayer 1692, and a third dielectric layer 1693. The third dielectriclayer 1693 includes a threaded portion 1694. The dielectric materialsused to form the first dielectric structure 1690 may vary in dielectricconstant, e.g., to aid in radiation directivity and impedance matchingand/or to achieve the optimum energy to tissue delivery. The shape, sizeand number of dielectric layers of the dielectric structure 1690(referred to hereinafter as the first dielectric structure 1690) may bevaried from the configuration depicted in FIG. 16.

As seen in FIG. 16, the third dielectric layer 1693 is configured to beseparable from the waveguide 1685, e.g., to allow for the removal andreplacement thereof. This provides the flexibility to modularly adaptand reconfigure the antenna assembly 1680, as desired, e.g., to matchthe impedance of the transmission line 15 to the impedance of tissue.

In some embodiments, as shown in FIG. 16, the energy applicator 1600includes a second dielectric structure 1620 coupled to the distal end ofthe third dielectric layer 1693 of the first dielectric structure 1690.Second dielectric structure 1620 has a generally dome-like shape, butother configurations may be utilized. Second dielectric structure 1620is similar to the second dielectric structure 120 shown in FIGS. 1-3 andfurther description thereof is omitted in the interests of brevity.

FIG. 17 shows an energy applicator (shown generally as 1700) inaccordance with an embodiment of the present disclosure that includes anantenna assembly 1780 including a waveguide 1785 with removabledielectric structures. Energy applicator 1700 includes a handle member1750 including a housing 1751, which are similar to the handle member150 and the housing 151, respectively, shown in FIGS. 1-3 and furtherdescription thereof is omitted in the interests of brevity. Energyapplicator 1700 may include a user interface 160 disposed in associationwith the handle member 1750.

Waveguide 1785 includes electrically-conductive walls 1784 of generallytubular shape, and may be formed of any suitable electrically-conductivematerial. The waveguide walls 1784 define a cavity 1786 therein andinclude a threaded portion 1752. The cavity 1786 is filled with adielectric structure (shown generally as 1790, with parts separated, inFIG. 17) including a first dielectric layer 1791, a second dielectriclayer 1792, and a third dielectric layer 1793. The second dielectriclayer 1792 includes a threaded portion 1795. The third dielectric layer1793 includes a threaded portion 1794. The dielectric materials used toform the first dielectric structure 1790 may vary in dielectricconstant, e.g., to aid in radiation directivity and impedance matchingand/or to achieve the optimum energy to tissue delivery. The shape, sizeand number of dielectric layers of the dielectric structure 1790(referred to hereinafter as the first dielectric structure 1790) may bevaried from the configuration depicted in FIG. 17.

As seen in FIG. 17, the second and third dielectric layers 1792 and1793, respectively, are configured to be separable from the waveguide1785, e.g., to allow for the removal and replacement thereof. Thisprovides the flexibility to modularly adapt and reconfigure the antennaassembly 1780, as desired, e.g., to match the impedance of thetransmission line 15 to the impedance of tissue.

In some embodiments, as shown in FIG. 17, the energy applicator 1700includes a second dielectric structure 1720 coupled to the distal end ofthe third dielectric layer 1793 of the first dielectric structure 1790.Second dielectric structure 1720 has a generally dome-like shape, butother configurations may be utilized. Second dielectric structure 1720is similar to the second dielectric structure 120 shown in FIGS. 1-3 andfurther description thereof is omitted in the interests of brevity.

FIG. 18 shows an energy applicator (shown generally as 1800) inaccordance with an embodiment of the present disclosure that includes anantenna assembly 1880 including a waveguide 1885 with removabledielectric structures. Energy applicator 1800 includes a handle member1850, and may include a user interface 160 disposed in associationtherewith. Handle member 1850 includes a housing 1851 including athreaded portion 1852. Handle member 1850 and the housing 1851 aresimilar to the handle member 150 and the housing 151, respectively,shown in FIGS. 1-3, except for the threaded portion 1852 of the housing1851 shown in FIG. 18, and further description thereof is omitted in theinterests of brevity.

Waveguide 1885 includes electrically-conductive walls 1884 a and 1884 bof generally tubular shape including a threaded portion 1888. Theelectrically-conductive walls 1484 b associated with the threadedportion 1888 are separable from the housing 1851. The waveguide walls1884 a and 1884 b define a cavity 1886 therein, and may be formed of anyelectrically-conductive material, e.g., copper, stainless steel,titanium, titanium alloys such as nickel-titanium andtitanium-aluminum-vanadium alloys, aluminum, aluminum alloys, tungstencarbide alloys, or combinations thereof.

The cavity 1886 is filled with a dielectric structure (shown generallyas 1890, with parts separated, in FIG. 18) including a first dielectriclayer 1891, a second dielectric layer 1892, and a third dielectric layer1893. The dielectric materials used to form the first dielectricstructure 1890 may vary in dielectric constant, e.g., to aid inradiation directivity and impedance matching and/or to achieve theoptimum energy to tissue delivery. The shape, size and number ofdielectric layers of the dielectric structure 1890 (referred tohereinafter as the first dielectric structure 1890) may be varied fromthe configuration depicted in FIG. 18.

As seen in FIG. 18, the third dielectric layer 1893 disposed inassociation with the electrically-conductive walls 1884 b is configuredto be separable from the housing 1851, e.g., to allow for the removaland replacement thereof. This provides the flexibility to modularlyadapt and reconfigure the antenna assembly 1880, as desired, e.g., tomatch the impedance of the transmission line 15 to the impedance oftissue.

In some embodiments, as shown in FIG. 18, the energy applicator 1800includes a second dielectric structure 1820 configured to be coupleablewith the distal end of the first dielectric structure 1890 and/or thedistal end of the waveguide walls 1884 b. Second dielectric structure1820 has a generally dome-like shape, but other configurations may beutilized, e.g., depending on the procedure to be performed, tissuecharacteristics of the target tissue or of the tissues adjacent thereto,etc.

Hereinafter, methods of directing energy to tissue, in accordance withthe present disclosure, are described with reference to FIGS. 19 through21. It is to be understood that the steps of the methods provided hereinmay be performed in combination and in a different order than presentedherein without departing from the scope of the disclosure.

FIG. 19 is a flowchart illustrating a method of directing energy totissue according to an embodiment of the present disclosure. In step1910, an energy applicator 100 is positioned for delivery of energy totarget tissue “T”. The energy applicator 100 is provided with asurface-contact detection device 130 that includes one or more opticaltransmitters 275 and one or more optical receivers 277. The energyapplicator 100 is operably associated with an electrosurgical powergenerating source 28. In some embodiments, the optical transmitters 275may be LEDs 276 and/or the optical receivers 277 may be photodiodes 278.

In step 1920, a determination is made whether a radiating portion 112 ofthe energy applicator 100 is disposed in contact with the target tissue“T” based on a determination of whether optical signals generated by theone or more optical transmitters 275 result in reflected optical signalsreceived at the one or more optical receivers 277.

If it is determined, in step 1920, that the radiating portion of theenergy applicator 100 is disposed in contact with target tissue “T”,then, in step 1930, energy is transmitted from the electrosurgical powergenerating source 28 through the radiating portion 112 to the targettissue “T”.

In an optional step 1940, a determination is made whether to transmit anelectrical signal indicative of an alarm condition using thesurface-contact detection device 130.

In some embodiments, an electrical signal indicative of an alarmcondition is transmitted based on an absence of optical signals incidenton each one of the one or more optical receivers 277. One or moreoperating parameters associated with the electrosurgical powergenerating source 28 may be adjusted in response to the electricalsignal. Some examples of operating parameters associated with the powergenerating source 28 that may be adjusted include temperature,impedance, power, current, voltage, mode of operation, and duration ofapplication of electromagnetic energy.

As illustrated in FIG. 20, step 1940 may further include steps 2041 and2042. In step 2041, monitor whether the radiating portion 112 of theenergy applicator 100 is disposed in contact with the target tissue “T”based on a determination of whether optical signals generated by the oneor more optical transmitters 275 result in reflected optical signalsreceived at the one or more optical receivers 277 of the surface-contactdetection device.

In step 2041, if it is determined that optical signals generated by theone or more optical transmitters 275 do not result in reflected opticalsignals received at the one or more optical receivers 277, causecessation of energy delivery from the electrosurgical power generatingsource 28 through the radiating portion 112 to the target tissue “T”.

FIG. 21 is a flowchart illustrating a method of directing energy totissue according to an embodiment of the present disclosure. In step2110, an energy applicator 100 is positioned for delivery of energy totarget tissue “T”. The energy applicator 100 is operably associated withan electrosurgical power generating source 28.

In step 2120, energy is transmitted from the electrosurgical powergenerating source 28 through the energy applicator to the target tissue“T”.

In step 2130, monitor whether a radiating portion 112 of the energyapplicator 100 is disposed in contact with the target tissue “T” basedon a determination of whether optical signals generated by one or moreoptical transmitters 275 of the surface-contact detection device resultin reflected optical signals received at one or more optical receivers277 of the surface-contact detection device 130. In some embodiments,the optical transmitters 275 may be LEDs 276 and/or the opticalreceivers 277 may be photodiodes 278.

If it is determined, in step 2130, that the optical signals generated bythe one or more optical transmitters 275 do not result in reflectedoptical signals received at the one or more optical receivers 277, then,in step 2140, cause cessation of energy delivery from theelectrosurgical power generating source 28 through the radiating portion112 to the target tissue “T”.

Although embodiments have been described in detail with reference to theaccompanying drawings for the purpose of illustration and description,it is to be understood that the inventive processes and apparatus arenot to be construed as limited thereby. It will be apparent to those ofordinary skill in the art that various modifications to the foregoingembodiments may be made without departing from the scope of thedisclosure.

What is claimed is:
 1. A method of directing energy to tissue,comprising: positioning an energy applicator for delivery of energy totarget tissue, the energy applicator operably associated with anelectrosurgical power generating source and having a waveguide, thewaveguide including electrically conductive walls that define a cavitytherein and a plurality of dielectric layers disposed coaxially with alongitudinal axis defined by the cavity; generating optical signals fromthe energy applicator; determining a position of the energy applicatorrelative to the target tissue based on a reflection of the generatedoptical signals; and transmitting energy to the target tissue via thewaveguide based on the determination of the position of the energyapplicator relative to the target tissue.
 2. The method of directingenergy to tissue of claim 1, further comprising transmitting anelectrical signal indicative of an alarm condition based on thedetermination of the position of the energy applicator relative to thetarget tissue.
 3. The method of directing energy to tissue of claim 1,further comprising terminating energy delivery from the electrosurgicalpower generating source via the energy applicator to the target tissuebased on the determination of the position of the energy applicatorrelative to the target tissue.
 4. The method of directing energy totissue of claim 1, further comprising adjusting at least one operatingparameter associated with the electrosurgical power generating sourcebased on the determination of the position of the energy applicatorrelative to the target tissue.
 5. The method of directing energy totissue of claim 4, wherein the at least one operating parameterassociated with the electrosurgical power generating source is selectedfrom the group consisting of temperature, impedance, power, current,voltage, mode of operation, and duration of application ofelectrosurgical energy.
 6. A method of directing energy to tissue,comprising: positioning an energy applicator for delivery of energy totarget tissue, the energy applicator operably associated with anelectrosurgical power generating source and having a waveguide, thewaveguide including electrically conductive walls that define a cavitytherein and a plurality of dielectric layers disposed coaxially with alongitudinal axis defined by the cavity; transmitting energy to thetarget tissue via the waveguide; generating optical signals from theenergy applicator; determining if the energy applicator is disposed incontact with the target tissue based on a reflection of the generatedoptical; and terminating energy delivery from the electrosurgical powergenerating source to the target tissue via the waveguide based on adetermination that the energy applicator is not disposed in contact withthe target tissue.
 7. The method of directing energy to tissue of claim6, further comprising transmitting an electrical signal indicative of analarm condition based on a determination that the energy applicator isnot disposed in contact with the target tissue.